TM 9-4940-444-14 & P
Lubricant must be selected In accordance with AGMA Standards. All oils must have a minimum viscosity Index of 90 and be
compounded with 3 to 10 percent acidless tallow or other suitable animal fats.
RECOMMENDED AGMA COMPOUNDS
Ambient Temperature (1)
(1) Pour-point of oil used should be less than the minimum ambient temperature expected.
(2) Worm speeds in excess of 2400 R P M or 2000 feet per minute rubbing speed may require force feed lubrication. Before starting a
new gear reducer, fill it to the oil level sight gage or plug.
Remove the gear bearing carrier, oil seal and shims.
The oil in a new unit should be drained at the end of two weeks
Remove the complete gear assembly.
operation and the gear case thoroughly flushed with a light
Note: All damaged parts must be replaced. Reassemble
flushing oil. Subsequently, change oil every 2500 hours of
in reverse order using the original or same size spacers and
operation or every six months, whichever occurs first. Where
operating conditions are severe, It may be necessary to change
If either the worm or gear has been damaged, replace with a
oil at intervals of one to three months.
new complete gearset. Check the set number and use only
APPROXIMATE OIL CAPACITY - IN GALLONS
matched sets for best results. All standard gearsets are
furnished in matched sets and are Interchangeable In the
reducer as such, regardless of the gear ratio. In manufacture,
unless the gearset is otherwise marked, each set is matched
with the worm on top ,t the gear. Looking from the input or
motor end of the worm, the gear markings are to the left. This
relationship must be maintained In assembly whether the
gearset is operated In a horizontal, vertical or other position.
If either member of the original gearset appears to be
The oil level should be maintained within the oil sight gage or
salvageable, it may be returned to our plant for Inspection, and if
plug when the reducer is not operating. Due to the effect of oil
found usable, be rematched with a new worm or gear to secure
agitation, it is not possible to obtain a correct oil level reading
a new gearset.
while the reducer is in operation.
REPLACEMENT OF BEARINGS:
It is necessary that the oil be clean and free of sludge at all
When tapered roller bearings are replaced, proceed as follows:
times to obtain long life from a gear reducer.
Measure the width of the original bearing being replaced.
Every precaution should be taken to prevent water and foreign
Measure he width of new bearing being installed. If the new
particles from entering the gear case.
bearing Is narrower than the old one, remove part of the shims
amounting o the difference. If new bearing is thicker, add shims
The unit must have the output shaft carefully lined up within the
In the same manner. All single row bearings should be
tolerances recommended by the manufacturer of the universal
assembled with the following looseness.
joints or couplings used. The base or mounting plate for the unit
RECOMMENDED BEARING LOOSENESS
must be fiat In order to provide a uniform support for the
mounting pads of the reducer. Mounting bolts must be tightened
uniformly. When properly lined up and bolted In place, the unit
should turn freely, except for slight friction caused by oil seals.
Shim feet to aline.
If it should become necessary to disassemble a reducer, either
Note 1: Looseness to be divided equally between each side
to replace bearings or worn or damaged parts, proceed as
of the unit for both worm and gear.
Note 2: Plus or minus .001 tolerance allowed.
End play on the worm shaft and gear shaft, due to wear or
shafts and remove coupling halves from shafts. Drain
differences In width of new bearings, may be eliminated by
oil from reducer.
removing Pr adding shims under the bearing caps. Care should
Note: Care should be taken to prevent misplacing or
be taken o maintain the original alignment of the gear set;
damaging any of the shims or gaskets. It is
bearing running tolerance must be maintained.
important that the shims be kept with their
respective caps and noted from which end of the
The thickness of shims can be determined simply from their
housing the cap was removed.
color is follows
Remove the worm bearing caps, oil seal, shims and
.003" thick shims are green
bearing cups from the housing. (These cups are a slip-
.005" thick shims are blue
fit and may be freed by lightly tapping the worm shaft.)
.010" thick shims are red
The worm may now be disengaged from the gear and
.020" thick shims are steel
removed from the housing.